Plant Pests

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Papaya Fruit Fly

Papaya Fruit Fly (Toxotrypana curvicauda)

The papaya fruit fly is the principal pest of Florida papaya. The insect was introduced into Florida in 1905, most likely from the West Indies on U.S.-bound papaya shipments. The fly has become established in southern Florida, and has spread to wherever this plant is grown. The larvae also feed on mango and milkweed as alternate hosts.

The adult fly is predominantly yellow marked with black. The female has a very long, slender abdomen with a greatly elongated curved ovipositor that exceeds the length of its body. The male resembles the female, although the abdomen is hairy and it lacks the ovipositor. The female deposits long (2.5 mm) slender eggs inside the fruit. The larva are white and typically resemble fruit fly larvae (cylindrical maggot shape, elongate, anterior end narrowed and somewhat recurved ventrally, with anterior mouth hooks). The pupae are stout and cylindrical with rounded ends, and vary in length from 8.5–12 mm.

During its life, the female is capable of laying 100 or more eggs. They are deposited during the evening or early morning in groups of ten inside young fruit and hatch in about 12 days. The young larvae feed on developing seeds and interior parts of the fruit. As the larvae mature, they begin to eat their way out of the fruit (about 16 days after hatch), drop to the ground, and pupate just below the soil surface. The mature flies emerge in about two to six weeks, depending upon humidity and temperature. Interestingly, unripe papaya juice is fatal to the larvae, so the flesh must be ripe when the larvae begin to migrate towards the surface. Fruit infected with papaya fruit fly larva will turn yellow and drop from the plant prematurely. Damage levels in Florida fluctuate between two and 30 percent of fruit infested during the spring-summer season.

By | 2017-09-11T15:49:33-07:00 November 29th, 2015|Plant Pests|0 Comments
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Mealybugs On Hibiscus

Mealy bugs are often a problem on hibiscus brought in from the outside for the winter. The plants are stressed from going from a high light situation to a low light one even though it is a sunroom, the light is not as bright and not as long during the winter. Keep it away from any other plants you may have in the house because they will spread.
Remove all flowers that may be blooming as well as any buds because mealy bugs and aphids prefer them.You can dab the with a cotton swab dipped in rubbng alcohol. That will remove their waxy protective coating. You will also find them on the undersides of the leaves as well. We suggest you go to the local garden center and purchase an insecticide safe for hibiscus indoors. It may give you control, not eradication and it appears you have a good infestation. Please do not use home remedies since they can actually cause more harm than good.When using the insecticide, make sure the plant is not in direct sun and was watered at least 12 hours prior to the application. Read and follow directions exactly. Monitor the plant every few days to see if there are any new mealybugs and remove again with rubbing alcohol. If you are not able to control, the best thing is to just pitch the plant and purchase a new one in the spring.
Whenever you bring a plant in for the winters, you should check it out for a couple of weeks in a room removed from others in case there are any hitchhikers. If you do keep the plant, keep the temperatures cool, about 60 degrees which will slow down any insect growth. Keep flower buds off the entire winter and do not fertilize again until April. You should cut the branch back by at least 1/3. It will keep the plant from getting leggy. Good luck!

By | 2015-11-13T20:33:41-08:00 November 28th, 2015|Plant Pests|0 Comments
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Chewing Damage

Its hard to say for certain with the amount of damage we see because several different organisms can chew plant parts; usually their damage is characteristic of the organism, which helps to narrow it down. It could either be snails/slugs, so look for slime trails on soil and leaves. Look for "worms" (caterpillars, or caterpillar-like organisms), and small beetles (may have black spots or stripes). The snail/slugs hide in the daytime so you have to look for them in their shaded/moist hiding places during the day, or look for them coming out to feed at dawn and dusk; pick them and dispose of them in a sealed bag. Worms can be disposed of in the same way, and you want to look for them on the underside of the leaves (sometimes stems) and look closely as they may blend in with the plant color, and usually leave droppings on the leaves/soil underneath them. Beetles will come and go so their harder to catch, but you can keep an eye out. If damage continues to get worse, you'll know the organism is still around, but if it doesn't progress at all, you'll know its come and gone and you don't need to do anything, except continue to observe and examine your plants once a week or more. Snail/slug baits don't work well unless they are applied exactly right and can be toxic to other organisms if you don't get the right stuff so we recommend just picking them. Caterpillars, when numerous can be controlled with a product that contains (Bt) but you can pick them too if not too many.

By | 2017-09-11T15:49:33-07:00 November 28th, 2015|Plant Pests|0 Comments
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Chewing Insect

The problem with chewing insects such as bug larvae or earwigs, grasshoppers, beetles, caterpillars (too numerous to name) etc. is they move about and often are difficult to spot among the foliage, but if there are black dots on the foliage, it is the excrement of chewing insects. Chewing insects can be large enough to see with the naked eye, but they can be red, orange, green, brown, black, etc. so look closely and pluck off any you see and dispose in a bucket of soapy water as long as the infestation is not too extensive. The problem with earwigs is that they are nocturnal and seek refuge in dark, moist areas during the day so spotting them is difficult. You are correct, that earwigs favorite food is newly emerging plants with tender foliage as well as flower buds. A simple method to trap them is to roll up a moistened newspaper in the late afternoon by your plants (earwigs are attracted to warm, dark, moist areas for cover and for their habitat) and dispose of the newspaper and earwigs in the trash in the morning or shake the earwigs out into a pail of soapy water. If it is extensive, you can spray with an organic control for chewing insects recommended by your local garden center such as Bt (Bt is a contact spray only) or Spinosad (7-10 day residual), but follow application directions. Also show some of these leaves or this photo to a horticulturist at your local garden center for confirmation of the problem as well as recommendations for control but make sure it is formulated for your plants.

By | 2015-11-28T11:07:46-08:00 November 28th, 2015|Plant Pests|0 Comments
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Scale Insects

We can't see clearly enought to be definitive, but this appears to be either scale insects or spider mites, nor can we say which species, from this photo. Neither of these plant pests usually cause major problems to plant health unless their population is very large. However, if you don't control them, and the conditions are right for their reproduction, they can get out of control. Keep your plant healthy and it will be better able to withstand the feeding. Control for scales varies by species or type of scale, but spider mite controls are mostly generalized. We've included web links for your reference in controlling these pests outdoors, but if this is a house-plant and the population is not large right now, we suggest you use a dilute solution of rubbing alcohol and water on a damp cloth and wipe the scales/mistes off of the leaf and stems. Don't over-do the alcohol as you can cause damage to the protective leaf cuticle with too high a concentration. You can also give the plant(s) a shower, literally, to clean off the pests, and any sticky exudate left by the scale feeding. Keep an eye out and continue to remove new developing pests. Otherwise, if the population numbers are high you can use pesticidal products, but they may not be very effective on the adult (covered) stage of the scale (they will work on the younger crawler stage if applied correctly), but they can be effective on mites. We recommend you use horticultural oils or pesticidal soaps whenever possible (you'll want to apply outdoors, but keep the plant in a shady location and make sure its watered a few hours before applying the oil to avoid burning the plant tissues)
For outdoor plants: http://www.ipm.ucdavis.edu/QT/scalescard.html
http://www.ipm.ucdavis.edu/QT/spidermitescard.html

By | 2015-11-23T18:53:34-08:00 November 23rd, 2015|Plant Pests|0 Comments
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Azalea Lacewing Or Spider Mite

We can't tell for certain by the photos, but the most prevalent insect attacking azaleas is the lace bug. Follow these tips. If you still can't tell, you may want to take a sample into your Extension office or a local garden center.

They are so named because of their lace-like wings. Both adult and immature bugs are usually found on the underside of leaves during April and May. They also produce a second cycle (brood) from July through September. Adult lace bugs are 1/8 inch long and 1/16 inch wide. This insect overwinters on your azaleas in the egg stage, and will hatch the following spring when the temperatures begin to warm.

Lace bugs damage azaleas by removing or sucking the sap from the plants as they feed. Damage is recognized by a blotched or spotted grayish appearance of the upper leaf surface. Eggs and spots of excrement resembling dark varnish will appear mostly on the underside of the leaves. Heavily infected leaves will turn yellow, then brown, and drop off prematurely.

A second insect pest of azaleas is spider mites or southern red mites. Spider mites are dark red and very small (0.4 mm long), and most active from January through June. Their damage closely resembles that of lace bugs. Spider mites feed on the lower leaf surfaces causing infested leaves to turn gray or brown and drop prematurely.

If you examine the leaves very carefully, you can usually see the mites or their webbing on the underside of the leaves. Another method of detection is to place a piece of white paper under several leaves. Tap the leaves on to the paper. If you have spider mites, then you’ll most likely see tiny red specks moving around on the white paper.

By | 2015-11-23T10:21:11-08:00 November 23rd, 2015|Plant Pests|0 Comments
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Minor Leaf Damage

This could be one of two things, and without seeing more samples it's hard to know which. After reading this if you want to pursue it further you might send two or three shots showing foliage with more damage and some shots of the back side of the leaves. Here are the two options:
1. Insect damage. If this is caused by an insect it would be one that chews (as opposed to an insect that sucks plant juices) and there are several active in northeast gardens right now. Japanese beetles, Asiatic garden beetles and earwigs all do this type of damage. If this sample is the worst of it, and if it doesn't get worse, this falls into the "acceptable level of damage" in a garden. (No garden is ever perfect. Let's face it, it's a jungle out there!) You might go out after dark with the flashlight app on your phone and look at this plant since most of the insects that chomp on leaves do so at night.

2. Fungal damage. Sometimes fungal damage resembles insect damage because as the tissue of the plant dies it falls away and looks very similar to a leaf that's been munched. What makes me think that this could be fungal is the light spot with the dark edges on the leaf to the right, and the "water soaked" appearance of tissue around the hole in the leaf in the center. That has the look of a leaf-spot fungus. If it is fungal you'll see other spots develop that first look yellow and/or water soaked, and then the tissue dries and falls away. Be sure that this plant isn't getting hit with an automatic irrigation system, or that the leaves aren't being watered frequently with a hose or sprinkler: frequent splashing of foliage with water is a prescription for leaf spot fungi.

So what to do? Here are your options: Monitor the plant and see if the problem continues. This is best done by marking some UNDAMAGED foliage with a twist-em or piece of yard and watching to see if it remains undamaged. Remove the worst of the damaged leaves to make monitoring easier as well. If the problem has stopped you can ignore it.

Secondly, if you find an insect that you suspect is doing the damage (see more than one so you know you're not "framing an innocent bystander") take that bug into your local garden center and decide on the treatment that suits you best.

Third, if you think it's fungal there are several organic fungicides that would help protect the rest of the plant including sulfur, copper and beneficial bacterias in products such as Serenade and Actinovate. Only spray the plants effected since you don't want to kill off all the good fungi in your garden. The same with the insecticide: there are more "good guys" in your landscape (insects and fungi) than "bad guys" and you don't want the beneficials to fall from "friendly fire." So to speak.

Send more photos if you wish to pin things down further.

By | 2017-09-11T15:49:34-07:00 November 22nd, 2015|Plant Pests|0 Comments
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Squash Bugs Or Squash Vine Borers

It is hard to tell what particular pest destroyed your squash plants. Squash Vine Borers and Squash bugs are very likely. It appears there are a few things going on here. Something is making a meal out of the leaves, and from appearance of the blossoms (as best we can see in this picture), there may be a pollinator issue as well. Squash bugs, and borers, adult beetles and nymphs, chew holes in leaves, and heavy infestations can reduce yields significantly

Squash Bug adults look like long brown stink bugs, with a flat abdomen. Nymphs are pale green to grey with a black head and legs. Older nymphs are covered in a grey powder. The eggs are oval, dark brown, and shiny, and are layed in clusters. Once they become numerous they are almost impossible to stop. Check with your local organic garden center for the best way to proceed.

Squash vine borer adults look like black wasps with red markings, they lay single eggs that hatch out as larva-- they look similar to a cream colored caterpillar. These larva tunnel into the crown and stems of the plant, and proceed to eat the juicy green inner plant tissue. The plant suddenly looks wilted and if the larva is allowed to go unchecked, can kill the plant in 3-4 days. Do daily checks of the crown areas, your looking for what appears to be piles of wet saw dust, this is actually frass, caterpillar poop. This is where they enter the stem and began to eat. If caught early you can gently cut a slit in the stem and pluck the culprit out.

By | 2015-11-16T23:56:05-08:00 November 16th, 2015|Plant Pests|0 Comments
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Aphids

This is probably common sap-sucking insect pests (found on many plants) called Aphids. Its hard to be 100% positive because we can't see the pest clearly enough in this photo, but they are a common pest of Rose, and when populations are high and they are developing thru their life cycle quickly, we see their shed skins stuck to the leaves like this (a result of their normal gradual metamorphosis from young nymph stages to adult). You'll want to look for the green (usually, but they can also be yellow, black, and peach colored) insects on the undersides of the leaves and on developing flower buds. The good news is, they are pretty easy to control. The females reproduce live young (minatures of themselves) in multiple numbers, and without being fertilized by a male, so they can reproduce quickly in the right environment. As they suck out the sugary plant sap they also excrete it, which makes the leaves sticky. We recommend you control this population as soon as possible by either spraying off with a high pressure spray of water, (you may have to do this several times on consecutive days to get them under control), and/or pick off the most infested leaves. If they contine to re-populate you'll need to keep up with them - wipe off by hand, use high pressure water spray, or use products like pesticidal soaps or horticultural oil. Be careful to follow the directions on all product labels. (The oil in particular can cause plant damage if applied incorrectly/under high temps and low moisture conditions). We've included a link with more info about Aphids and ways to control them.
http://www.ipm.ucdavis.edu/QT/aphidscard.html

By | 2015-11-13T20:51:54-08:00 November 15th, 2015|Plant Pests|0 Comments
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Chewing Insect

The problem with chewing insects such as bug larvae or earwigs, grasshoppers, beetles, caterpillars (too numerous to name) etc. is they move about and often are difficult to spot among the foliage, but if there are black dots on the foliage, it is the excrement of chewing insects. Chewing insects can be large enough to see with the naked eye, but they can be red, orange, green, brown, black, etc. so look closely and pluck off any you see and dispose in a bucket of soapy water as long as the infestation is not too extensive. Another chewing insect is the earwig, but it is nocturnal and seeks refuge in dark, moist areas during the day so spotting them is difficult. Earwigs favorite food is newly emerging plants with tender foliage as well as flower buds. A simple method to trap them is to roll up a moistened newspaper in the late afternoon by your plants (earwigs are attracted to warm, dark, moist areas for cover and for their habitat) and dispose of the newspaper and earwigs in the trash in the morning or shake the earwigs out into a pail of soapy water. If it is extensive, you can spray with an organic control for chewing insects recommended by your local garden center such as Bt (Bt is a contact spray only) or Spinosad (7-10 day residual), but follow application directions. Also show some of these leaves or this photo to a horticulturist at your local garden center for confirmation of the problem as well as recommendations for control but make sure it is formulated for your specific plants.

By | 2015-11-15T23:30:50-08:00 November 15th, 2015|Plant Pests|0 Comments
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